A typical computer system has a housing that surrounds its internal components including the printed circuit boards used to configure optional features of the computer system. The configurable circuit boards are coupled to the computer system's chassis or motherboard through an internal connector interface. The circuit board also may have an external connector interface through the housing so that it can be connected to a peripheral component or various other devices.
The housing provides an enclosure that helps protect the internal components of the computer system and also shields the surrounding environment from the electromagnetic radiation (EMI) generated by the computer system. Openings in the housing, such as that for the external connector interface of a circuit board, are typically sealed to prevent or limit EMI leakage from the computer system.
Thus, a disadvantage to the prior art is that in order to modify or upgrade a computer system--for example, to install a new circuit board--it must be shut off, the housing opened, the circuit board inserted into place and the proper connections made, and the housing reassembled and closed.
It is commonplace for multiple computer systems to be situated in a single location. For example, for economic or space efficiency reasons, multiple computer systems are typically located in a single air-conditioned room. This also facilitates connecting the computer systems to each other by cables. To optimize use of the available floor space, the computer systems are tightly quartered and are often placed one on top of another in racks.
The above disadvantage in the prior art is compounded when a modification to one or more of these computer systems is needed. For example, when the computer system is installed in a rack, it must be turned off, uncabled from the other computer systems, removed from the rack and placed somewhere else in order to perform the necessary work, the housing opened, the circuit board inserted into place and the proper connections made, the housing reassembled and closed, the computer system reinstalled in the rack and recabled to the other computer systems, and then turned back on. This series of operations is burdensome and time consuming, and is further aggravated by the close quarters in which they are performed. In addition, it is desirable to keep the computer system powered on while it is being worked on, in order to minimize the disruption to users and to perturb the other computer systems as little as possible.
Some prior art techniques attempt to address the problems described above by making the housing easier to open and close and by allowing the circuit board to be removed and installed without having to shut down the computer. However, these techniques only address a portion of the overall problem; it is still necessary to uncable the computer, remove it from the rack, find a place to work on it, reinstall it in the rack, and recable it to the other computer systems. In addition, in those instances in which the computer is not shut down and the housing is open, there is a significant breach of the EMI insulation and therefore substantial EMI leakage.
Other prior art techniques attempt to address the problems described above by equipping the rack with sliding arms that hold the computer systems. In this approach, when work is to performed on a computer system, it can be slid from the rack and supported by the sliding arms. However, it is still often necessary to uncable the computer system in order to allow it to be moved. In addition, some racks are more than eight feet tall, making it difficult to work in place on the computer system. In any event, it is still necessary to open and close the housing to install the new circuit board, which requires that the computer system be shut off or otherwise allows substantial EMI leakage. Hence, these prior art techniques also do not provide a solution to the overall problem.
Accordingly, what is needed is a technique that facilitates modifying or upgrading the internal components of a computer system. What is also needed is a technique that addresses the above need and is suited for use in a close quarters environment, in particular one in which multiple computers are present and situated, for example, in a rack. What is further needed is a technique that addresses the above needs and also minimizes the disruption to users and other computer systems, by allowing work to be performed while the computer system is powered on and cabled to other computer systems and minimizing, for example, EMI leakage. The present invention provides a novel solution to the above needs.
These and other objects and advantages of the present invention will become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiments which are illustrated in the various drawing figures.